Hydrocarbon oils



Patented Nov.

"Nl'lED STATES PATENT I OFFICE nrnnocannon orLs Bruce B. Farrington andJames 0. Clayton,

Berkeley, and Burt H. Etzler, Albany, Calif., assignors to Standard OilCompany of California, San Francisco, .Calif., a corporation of DelawareNo Drawing.

Application December-3, 1942, Serial No. 467,779

21 Claims. (c1, 252-53).

This invention relates to new and useful compositions or matter and tomethods or preparing the same. In particular, it relates to compositionscomprising hydrocarbons of the lubricating oil class,in major part, inwhich are dissolved or suspended minor amounts'of certain metal salts oforganic aliphatic carboxylic acids, either alone or in admixture withother compounding agents of the same or different type.

This application is a continuation-in-part of,

our copending' application Serial No. 322,946, filed March 8, 1940,nowPatent No. 2,349,817.

It has long been the desire of the lubricating oilcompounding art toobtain an oil, particu larly of petroleum origin, which alone or withthe addition of relatively small amounts of compounding agents, wouldresist deterioration or degradation when subjected for long periods oftime to high temperatures and pressures,in the presence, of metals, airor oxygen, or hydrocarbon partial combustion products. Deterioration ofthe character referred to here manifests itself in diverse efiects,dependent upon the nature and degree of refinement of the hydrocarbonoil and upon the environment to which it is subjected, but reference maybe made to Diesel engine' piston ring sticking, in which the exposure ofa lubricating oil to such temperatures as 425-650 F., in the presence ofoxidizing com bustion gases at pressures as high as 750-1150 lbs/sq.in., causesthe deposition of oil degradation products of such acementitious character as toeffectively take piston rings out ofservice; to the deposition of sludge from automobile crankcase oils,apparently as the result of oxidation and/or polymerization phenomena;and to the corrosion of metal bearing surfaces, apparently as a resultof phenomena which cause the formation of organic acidic products. Thissituation is aggravated by the' fact that improvements in the mechanicalarts have brought about increasing severity in the conditions to whichhydrocarbon oils are subjected, and by the fact that oil compoundingdesigned to effect a stability in one direction often brings about amarked instability in another.

It has been found that the addition to a lubricating oil of smallamounts of a. metal salt of an aliphatic carboxylic acid, carrying asubstituted or unsubstituted carboxylic acid group in addition to thesalt-forming carboxylic acid group and carrying in addition to saidgroups an ether substituent or a keto substituent, or a sulfur, seleniumor tellurium analogue of said other substituent or keto substituent,attached tin and zinc have to'an aliphatic carbon atom, brings about animproved stability in hydrocarbon oils when the same are subjected tohigh temperatures or pressures in the presence of oxygen and metals;such acids correspond in general to the type HOOC-(CHz) :r-COOH, inwhich n is a whole number; in which there may or may not be alkyl, aryl,aralkyl or aliphatic carbocyclic substitution to increase oilsolubility; and in which a polar group selected from' the classconsisting Of. -'-OR1, -SR1, SeR1, TeR1, =0, :8, =Se and =Te issubstituted in a position alpha, beta, gamma, delta or even epsilon tothe carbon atom or a salt-forming carboxylic acid group,

the effectiveness for the desired purpose decreasing in the order'ofpositions asrecited. In the above class of groups -OR1, SR1, etc., Rlrepresents an organic group of'essentially hydrocarbon structure such asalkyl, aryl, alkaryl. aralkyl and aliphatic carbocyclio groups. Pref--erably at least one of said groups is located not more than three carbonatoms from a salt-forming carboxyl group.

Viewed from another standpoint, the salts of this invention are metal.salts or polar substituted polycarborwlic acids capable, ofrepresentation by the partial formulaaooo-c'r-cooxvi in which M is ametal, including the hydrogen equivalent of a polyvalent metal, R ishydrogen,

a metal, ammonium, or an organic group, the

groups COOM and R000 are attached to 9.11-'

phatic carbon atoms, the carbon atom to which X is attached is analiphatic carbon atom, preferably alpha, beta or gamma with respect tothe COQM group, and X is selected from the group consisting of -OR1,SR1, -SeR1, 'IleR1'.

=0, =8, =Se and =Te, wherein R1 is as defined and =I'e and used in theformot their metal salts there may be mentioned malonic, succinic,

glutaric, adipic and sebaclc acids; the alkyl and alkylene homologue: ofthese acids. such as pentylmalonic. cetylmalonic, isopropylsuccinic,cetensylsuccinic, and eicosenylsuccinic acids; and

' various polar substituted (including unsaturated) acids of the sameseries, such a malic, maleic,

tartaric an citric acids.

There are given below the structural formulae of a few typical salts ofthis invention:

(1) Calcium alpha-cetoiwmalonate coo cans- 04 Ca coo (2) Calciurn cetylalpha-methoxymalonate a COO-OM euro-en -o-cm occurs, coconut (3) Calciumcetyl ketomalonate (calcium can j mesoxalate) ('7) Calciumalpha-eetylthiomalonate (8) Calcium alpha cetylselenylmalonate (9)Calcium alpha cetyltellurylmalonate (10) Calcium cetylthionomalonate(11) Calcium cetylselenomalonate (12) Calcium cetyltelluromalonate (13)Calcium cetyl alpha-methylthiosuccinate (14) Calcium cetylalpha-methylselenylsuccinate (15) Calcium cetylalphaamethyltellurylsuccinate Compounds '7, 8 and 9 are the thio, selenoand telluro analogues 01 compound 1, wherein the oxygen of the cetoxygroup is replaced by sulfur, selenim and tellurium, respectively.Compounds 10, 11 and 12 are similarly the sulfur, selenium and telluriumanalogues of compound 3,' and compounds 13, 14 and 15 are the sulfur,selenium and tellurium analogues of compound 5.

The ether substituted malonic and succinic acids and the sulfur,selenium and tellurium analogues of these ether substituted acids (8,

'Se and Te substituted ior 0 in the group 0R1) can-be prepared by wellknown methods. For

instance, alkoxy malonates can be prepared by the method of Wrslicenusand Miinzesheimer (Berichte 1898' vol. 31, p. 552) by condensin alkoxyacetate esters with oxalate esters in dry ether in thepresence of sodiumfollowed by a carbon monoxide cleavage to yield the alkoxy malonateesters. The es s ca b saponifled to yield the acids.

The dialkoxyand diaryldzysmalonic acids can be prepared by treatingdibromonialonate esters with alcoholic solutions of sodium alk'oxides orsodium phenates. 1

The alkoxysuccinic acids can be preparedby reacting maleate or fumarateesters with the appropriate alcohol in the presence of a small amount ofthe sodium alcoholate. This process yields the ester which can besaponifled to yield the acid.

The alkylthiosuccinic acids can be prepared by reacting bromosuccinicacid salts with an alkali mercaptide.

The keto, thiono, seleno' and telluro malonic and succinic acids can beprepared by well known methods. For instance, salts of ketomalonic acidcan be prepared by oxidizing malonate esters with nitrogen tetroxide toform the mesoxalate ester (ketomalonate) followed by a partial wsaponiflcation to yield the .half ester. Salts of ketosuccinic acids canbe prepared by condensing oxalate and acetate esters in the presence oisodium alcoholates in anhydrous ether totorm the corresponding esterwhich can be partially saponifled.

From the various acids prepared as described above, the normal and acidsalts and the salts of partial esters can be readily prepared by methodswell known in the art.

As exemplified by the above structural tormulae, the salts of thepresent invention preferably have in their molecules an oil-solubilizinggroup, illustrated above by the cetyl group. Other oil-solubilizinggroups, such as other alkyl groups, aryl groups, alkyl aryl groups, arylalkyl groups and cycloaliphatic groups may also be employed. Also, otherpolar groups may be present in the salt molecule in addition to theindicated ether,

keto, and the like groups.

Illustrative examples of compositions of the invention are as follows:

1. 99% SAE parailinic oil +l% Ca a-cetyloxymalonate 2. D tto +l% Zna-dlamylphcnoxymalonate 3. DlflZO.-- +l% 0a a-cetylthiomalonate 4. Ditto+l% 0a cetyl a-methoxysuccinate 5. Ditto +l% Ba cetyla-methylthiosuccinate 6. 99% SAE 30 naphthemc w oil +l% Galaurylmesoxalate 7. Ditto +l% Mg dodecyl u-thionosuceinate 8. Ditto +l%Ba cetyl u-methylselenylsuccinate 9. 99% SAE 30 mixed base 7 oil +l% Cac-cetyloxymalonate l0. Ditto +l% Zn o-diamylphenoxymalonate ll. Ditto+l% Ca wcctylthiomalonate l2. Ditto +17 Ba cetyla-methylselenylsuccinate 13. 98% SAE 30 naphthenic{+1% Cao-cetyloxymelonate oil +l% Ca cetylphenate 14 Ditto {+l% Cae-cetylthiomalonate +l% Ca eetylphosphate Ditto {+l% Ba cetyla-methylthiosuccinatc +l% Ca cetylphenol sulfonate 16 Ditto +l% Mgdodeeyl c-thionosuccinate +l% dicetyl sulfide 17 Ditto {+l% Ca laurylmesoxalato +l% dihydroxy diphenyl sulfide These and other oils have beenfound to be highly useiul; among other things they exhibit-an enhancedstability toward air at high temperatures and pressures, or lesstendency to cause piston v ring sticking, or reduced corrosion ofbearings of the type of cadmium-silver and copper-lead bearings, or acombination of such valuable proper 0.2% and 2.0% of the agents, byweight'based on the oil, are preferable, dependent upon the degree ofinherent tendency toward degradation of the oil itself or as otherwisecompounded;

amounts higher than about 5.0% are regarded as unnecessary in the bestpractice of the invention.

A feature of the invention is in the preparation and distribution ofbases or concentrates containing relatively large proportions of theadditive agents in admixture with hydrocarbon oils of the lubricating orless viscous types or, if more suitable in conjunction with certainother agents, by reason of solubility relationships or the like, inadmixture with aromatic hydrocarbons or with alcohols, esters, ketonesor others, generally of the aliphatic series. Admixtures of the agentsand lubricating oils or other solvents or carriers containing upward of50% of the essential agents, by weight may be thus prepared anddistributed, for later blending with the particular lubricating oilmedia desired to be put to use, as occasion demands. In the preparationof either the finished oils of the invention or the bases orconcentrates referred to, complete or clear and homogeneous solution isnot always necessary; blending agents or homogenizers may be employed ifdesirable, to prevent sedimentation of the more oil-insoluble of theagents, but it has been found the possible detrimental effect of thepresence of filterable insoluble materials of this character, if indeedpresent, is determined largely by the particular conditions attendingthe contemplated use, and that their presence is not in all casesdeleterious to the functioning of the compositions in their intendedmanner.

Herein and in the claims, wherever the term "ether or keto is used toidentify a substituent,

group or radical, it is intended to identify the v group OR1 or =0,respectively, wherein the free oxygen valency or valencies are attachedto an aliphatic carbon atom other than that of a carboxyl group andwherein R1 is as defined above. The sulfur, selenium and tellurium aha--logues of these substituents., as referred to herein and in the claims,constitute the two classes of substituents: (l) Sl ti, SeRn and -TeR1,and (2) =5, =Se and le, respectively, in which sulfur, selenium ortellurium take the place of oxygen in the ether (-08.1) and keto (=0)groups and R1 is as defined above.

While the character of the invention has been given in detailandnumerous illustrative examples of the preparation and utility of thecompositions of the invention have been described, this has been donelargely by way of illustration and with the intention that no limitationshould be imposed upon the invention thereby. It will be obvious tothose skilled in the art that numerous modifications and variations ofthe above illustrative examples may be eifected in the practice of theinvention, which is intended to be of the scope of the appended claims.

We claim:

1. A liquid hydrocarbon oil of the lubricating class, normally tendingto deteriorate at operating temperatures encountered in the lubricationof internor combustion engines, containing a small amount, sufficient toretard the said deterioration, of a metal salt of an aliphaticpolycarboxylic acid substituted on an aliphatic carbon atom not morethan about three carbon atoms removed from a salt-forming carboxyl groupby a substituent selected from the class consisting of ether and ketosubstituents and the sulfur, selenium and tellurium analogues of saidether and keto substituents.

2. The oil of claim 1, wherein said substituent is an ether group.

3. The oil of claim 1, wherein said substituent is a. keto substituent.

4. A liquid hydrocarbon oil of the lubricating class, normally tendin todeteriorate at operating temperatures encountered in the lubrication Iformula SR1,wherein R1 is a radical selected from the group consistingof alkyl, cycloaliphatic, aryl, aralkyl and alkaryl radicals.

5. A liquid hydrocarbon oil of the lubricating class, normally tendingto deteriorate at operating temperatues encountered in the lubricationof internal combustion engines, containing a small amount, sufiicient toretard the said deterioration, of a polyvalent metal salt of analiphatic dicarboxylic acid, said acid containing an oil-solubilizingsubstituent and being substituted on an aliphatic carbon atom not morethan about three carbon atoms removed from a salt-forming carboxyl roupby a substituent selected from the class consisting of ether and ketosubstituents and the sulfur, selenium and tellurium analogues of saidether and keto substituents.

6. A liquid hydrocarbon oil of the lubricating class, normally tendingto deteriorate at operating temperatures encountered in the lubricationof internal combustion engines, containing a small amount, sufiicient toretard the said deterioration, of a polyvalent metal salt of analiphatic tricarboxylic acid, said acid containing an oil-solubilizingsubstituent and being substituted the sulfur, selenium and telluriumanalogues of said ether and keto substituents.

7. A composition of matter, comprising a major proportion of ahydrocarbon oil of lubricating viscosity and a small amount, suiilcientto retard the deterioration of the oil, of a compound represented by thepartial formula wherein M is a metal, the group COOR is selected fromthe class consisting of free carboxyl, salt formin carboxyl and carboxyester groups, both nooc-d-cooM wherein M is the hydrogen equivalent of a'polyvalent metal, COOR is selected from the class consisting of freecarboxyl, salt-forming carboxyl ether group. 10. The composition ofclaim 8, wherein X is 10 the sulfur analogue of an ether group.

11. The composition of claim 8, wherein X is I a keto substituent.

12. The composition of claim 8, wherein X is selected from the classconsisting of OR1, .SR1, SeR1 and TeR1, wherein R1 is a high molecularweight, oil-solubilizingether-forming organic group. i

13. A petroleum lubricating oil containing about 0.1 to 5 per cent byweight based on finished oil of a polyvalent metal salt of an alkoxysubstituted malonic acid, the alkyl group of the alkoxy substituentbeing a higher alkyl group capable of imparting oil-solubility to thesalt.

14. Thecornposition ofclaim 13, wherein said polyvalent metal is analkaline earth metal.

15. The composition of claim 13, wherein said polyvalent metal iscalcium.

16. A petroleum lubricating oil containing about 0.1 to 5 per cent byweight based on flnished oil of a. compound of the structure o=c c=COORI RzOOC 'weight oil-solubilizing organic radicals.

1']. A petroleum lubricating oil containing about 0.1 to 5 per cent byweight based on finished oil of a polyvalent metal salt of an alkoxysubstituted succinic acid, the alkyl group of the alkyl ethersubstituent being a higher alkyl group capable of imparting oilsolubility to the salt.

18. The composition of claim 1'7, wherein said polyvalent metal is analkaline earth nietal.

19. A petroleum lubricating oil containing about 0.1 to 5 per cent byweight based on finished oil of a polyvalent, metal salt of a partialester of a keto substituted succinic acid, the ester group of saidpartial ester containing a high mo lecular weight oil-solubilizingorganic radical.

20. A concentrated dispersion in mineral oil of a metal salt of analiphatic polycarboxylic acid substituted on an aliphatic carbon atomnot more than about three carbon atoms removed from a salt-formingcarboxyl group by a substituent stituents.

"bricant of an internal combustion engine and a small amount each,suflicient to retard said deterioration and deposition, of a polyvalentmetal salt of an alkylated phenol and a polyvalent metal salt of analiphatic polycarboxylic acid substituted ina position not more thanabout three carbon atoms removed from a salt-formingcarboxyl group by asubstituent selected from the class consisting of ether and ketosubstituents and the sulfur, selenium and tellurium analogues of .saidether and keto substituents.

BRUCE B. FARRINGTON.

JAMES O. CLAYTON.

DORR H. ETZLER.

